Cerebral aneurysms are abnormal localized swellings of the wall of an artery in the brain. One method of treating such aneurysms is an endovascular intervention. The basic principle of such an intervention is to slow down the blood flow inside the aneurysm using an endovascular device for deployment. This may cause a thrombotic reaction inside the aneurysm. Known techniques for performing the endovascular intervention are, for example, coiling, or the introduction of a flow diverter. Computer-aided tools are available to plan the positioning of an endovascular device for deployment before an operation. Present procedures for endovascular planning are carried out before an endovascular intervention. Nevertheless, the incorrect placement of an endovascular device for deployment during the intervention also implies some risk. The patent publication WO 2011/121516 discusses such methods.